KT88s in 200S?

[MK Ultra]

My bass player has a 200S head with a SS rectifier and 6550s.  I love the way it sounds, but lately I've been wondering how it would sound if I swapped the 6550s for KT88s.  Anybody try this?  Also, does the amp need to be modified at all to run KT88s or is it doable with just a bias adjustment?  Thanks.

[Bill Matthews]

The KT88's are just the European designation for the 6550, but there is a substantial difference in sound depending on which KT88's you use.  I use the GEC KT88's, I feel they sound best, and were originally the KT88 that came in the amp from the factory.  If you are changing over to the KT88's, do yourself a favor...don't waste your time, or the techs time to rebiasing the amp, by using a wannabe copy of the GEC's, just cough up the money and get the real thing... You WON'T regret it.

[Mark Ratcliffe]

Bill, Where can you buy these?

[Sanford]

I switched my 100s from 6550's to KT88's it was like night and day. Go to tubestore.com great prices.

[Greg Z]

I just dream of the day I can afford to
stick a matched Quad of nos Gec Kt-88's in my
1200's

[Bill Matthews]

The GEC's are available all day on Ebay, just type in KT88 in the smart search window. I have scored a matched pair for as little as $75, and have paid as much as $200 for a pair.  Trust me they are worth the money.

[Greg Z]

Finding a Mp of Gec kt-88's is one thing,
finding a Mq is another story.
Saw a Quad of Nos Nib go off at over
850.00, too rich for my blood.
Drool

[Rocketboy]

I put a Mp of Svet KT88's in my 200S (with ss diodes for rectifier) and they sound great.  I've only had them in a few months, so the test of time has not been met as yet; so far - wonderful.  Per the data sheets, the KT88 can stand more plate current than the 6550.  In any event, the bias should be set every time new finals are installed, and then reset again after several hours of operation regardless of the tube type.